CVE-2021-42972 is a high-severity vulnerability affecting NoMachine Server, specifically versions between 4.0.346 and 7.7.4. This vulnerability allows local attackers to exploit a buffer overflow in the IOCTL handler 0x22001B. If successfully exploited, attackers may execute arbitrary code in kernel mode or cause a denial of service, which can lead to memory corruption and an operating system crash. The CVSS score for this vulnerability is 8.8, indicating a significant risk to organizations.
Risk to organizations includes potential unauthorized access to sensitive information and system functionality. Given the local attack vector and low privileges required, the ease of exploitation could pose serious threats to system integrity and availability. Organizations must act swiftly to address this vulnerability as part of their security posture.
Currently, there are no known public exploits for this vulnerability, but the nature of the flaw poses a real threat to affected systems, urging defenders to prioritize remediation efforts. Organizations should patch affected systems immediately to mitigate risks associated with this vulnerability.
The urgency for defenders cannot be overstated; organizations should prioritize patching immediately to prevent potential exploitation.
Vulnerability Details
The official description of CVE-2021-42972 states: 'NoMachine Server is affected by Buffer Overflow. IOCTL Handler 0x22001B in the NoMachine Server above 4.0.346 and below 7.7.4 allow local attackers to execute arbitrary code in kernel mode or cause a denial of service (memory corruption and OS crash) via specially crafted I/O Request Packet.'
This vulnerability has been classified as a buffer overflow issue, with a CVSS score of 8.8, indicating it is of high severity. The affected product is the NoMachine Server, which is used for remote desktop connections. The vulnerability was published on December 7, 2021, and falls under the CWE classification of CWE-120.
Technical Analysis
The root cause of the vulnerability stems from insufficient input validation in the IOCTL handler, which processes I/O Request Packets. Attackers can exploit this weakness through local access, enabling them to send specially crafted requests that trigger buffer overflow conditions.
The attack vector is local, meaning an attacker must have physical or administrative access to the device to exploit the vulnerability. The attack complexity is rated as low, and only low-level privileges are required to initiate the attack, with no user interaction necessary.
The impacts of successful exploitation are significant, affecting confidentiality, integrity, and availability of the system. An attacker could gain control over the operating system, leading to potential data breaches and service interruptions.
Risk & Impact Analysis
Real-world deployment risks include the potential for local attackers to exploit the vulnerability to gain unauthorized access to sensitive data and system functions. The blast radius could be significant, especially in environments where NoMachine Server is used for remote access to critical internal systems.
Organizations should consider the urgency based on the CVSS score of 8.8, which indicates a high risk that necessitates immediate attention. This vulnerability poses a serious threat, and swift action is required to mitigate potential exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of NoMachine Server are those between 4.0.346 and 7.7.4. Organizations should ensure that they have upgraded to the latest version to mitigate any risks associated with this vulnerability.
Mitigation & Remediation
Organizations should prioritize patching the NoMachine Server to the latest version. This is a crucial step to mitigate the risks posed by CVE-2021-42972. If immediate patching is not feasible, consider implementing workarounds such as restricting local access to the server or monitoring for unusual activity on affected systems.
For further assistance, organizations can engage in penetration testing to ensure that their systems are secure against potential vulnerabilities.
Detection Guidance
Organizations should monitor their logs for any indicators of exploitation attempts, such as unexpected I/O Request Packets. Additionally, behavioral anomalies in system performance may indicate potential exploitation of this vulnerability. Implementing network signatures to detect malicious activity related to this vulnerability is also recommended.
AppSecure Threat Intelligence Insight
CVE-2021-42972 serves as a reminder of the importance of rigorous vulnerability management practices. The potential for local exploitation of this buffer overflow vulnerability underscores the need for organizations to continuously assess their security posture and implement timely patches.
This vulnerability reflects a trend in exploiting local access points within software components. Organizations should remain vigilant in monitoring their systems and consider engaging in penetration testing methodology to proactively identify and remediate similar vulnerabilities.
Additionally, organizations can benefit from best practices outlined in the vulnerability management program design to strengthen their defenses against emerging threats.
Finally, it is essential for organizations to keep abreast of the evolving threat landscape as they engage in security testing best practices to effectively mitigate risks associated with vulnerabilities like CVE-2021-42972.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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